so this weekend I discovered (with the help of a lot of rain) that my fan vent on the roof has a leak. Never should happen on a 2015 model. But I need to fix it correctly. I know there are a lot of products on the market; from spray sealant to different types of caulk & silicones. I just want to scrape all the original silicone & re apply something new. Can anyone suggest what may be best? It is a very slow small leak, but you know water.....it doesn't take much to cause considerable damage to the inside of your PUP> Thank you.